Kingdom Fungi - Eukaryotic.

Kingdom Fungi - Eukaryotic

Structure Most are multicellular Hyphae = threadlike filaments
Basic structural unit of a fungus Mycelium = network of hyphae Cell walls made of chitin (pronounced “KY-ten”) Few unicellular species (i.e. yeasts)

Structure cont… Heterotrophic Extracellular digestion; use enzymes
Decomposers = saprophyte (live off dead things) “sapro” = dead in Latin Parasites = absorb nutrients from living host Haustoria = specialized hyphae that penetrate & grow in the host cells Mutualism = helps themselves & the host i.e. – roots of plants (see also mycorrhizae)

Structure: Reproduction
Asexual Fragmentation = pieces break off and form new whole fungi Budding = mitosis causes a new individual to form; eventually it separates from the parent Sexual Spores Produced by sporangia (sac in which spores are made) Often the only part of a fungus you can see

Adaptations for Survival
Spores are very lightweight Huge numbers are produced from 1 parent Spread by many different ways (water, wind, birds, insects)

Types of Fungi Zygomycota Ascomycota Basidiomycota Deuteromycota

Phylum Zygomycota “Zygomycetes”
1500 species i.e. bread mold = Rhizopus stolonifer Mainly decomposers Both sexual and asexual stages of life cycle Asexual reproduction with spores Sexual reproduction with thick-walled spores Stolons = hyphae that grow horizontally along the surface of a food source Rhizoids = hyphae that grow vertically down into a food source Forms zygospores = thick-walled sexual spores that are adapted to withstand unfavorable conidtions

Reproduction in Zygomycota

Phylum Ascomycota “Sac Fungi”
30,000 species = largest group i.e. morels & truffles i.e. plant diseases = apple scab & dutch elm disease Animal diseases = yeast infection, ring worm Both sexual and asexual stages of life cycle Ascus = sac-like structure in which sexual spores are produced Ascospores = spores that develop in the ascus Conidiophores = hyphae that rise up from the mycelium Conidia = asexual spores that develop from the tips of the conidiophores Produce spores in groups of 8; are haploid

Ascomycota cont… Unicellular fungus = yeasts
Reproduce asexually by budding Important for baking and brewing Also important in genetics; have large chromosomes Vaccine for hepatitis B = splicing human genes with yeast cells

Phylum Basidiomycota “Club Fungi”
25, 000 species = most familiar i.e. pizza mushroom = Agaricus bisporus Both sexual and asexual stages of life cycle Basidia = club-shaped hyphae in which sexual spores are produced Usually produces a short-lived reproductive structure i.e. mushroom cap & stalk Basidiospores = sexual spores produced by the basidia Produce spores in groups of 4; are diploid

Phylum Deteromycota “Incomplete Fungi”
25, 000 species = no known sexual stage in life cycle i.e. Penicillium = antibiotics Only asexual reproduction; sexual stage has not been observed by a mycologist “myco” = fungus “ologist” = one who studies Uses = making soy sauce; Penicillin, citric acid  gives soft drinks, candies & jellies their tart flavor; used to make blue-veined cheeses

Mutualistic Relationships with Fungi
Both organisms benefit from the relationship

Mycorrhizae Symbiotic relationship in which a fungus lives in close relationship with roots Fungal partner is usually from basidiomycota; some are from zygomycota Fungus increases the amount of nutrients that move into the plant by increasing the absorbing surface area of the plant’s roots i.e. Copper & Phosphorous

Mycorrhizae cont… Also may help maintain water in the soil around the plant Fungus receives organic nutrients from the plant i.e. sugars & amino acids 80-90% of all plant species have a mycorrhizae associated with their root systems Relationship makes plants larger & more productive Some plant species cannot survive without them! i.e. orchid seeds will not germinate into a plant without a mycorrhizal fungus to provide them with H2O and nutrients.

Lichens 20,000 species of lichens
Symbiotic association between a fungus and a green algae Fungal partner is usually from Ascomycota Fungus forms a tangled web of hyphae in which the algae grow Forms a spongy structure that looks like 1 organism. Grow very slowly – very large lichens are thought to be thousands of years old

Lichens cont… Need only light, air, and minerals to grow
Photosynthetic green algae provides itself & the fungus with energy/food Fungus retains moisture and absorbs minerals Can live in harsh & barren habitats Usually among the first organisms to live in an area i.e. arid deserts, on bare rocks in the hot sun or bitter cold winds; just below the timber line on mountain peaks; and in the arctic tundra!

Fossils Fossils show how fungi evolved
Fossils of fungi are rare because they’re made of soft material (chitin isn’t as durable as cellulose) Oldest fossils of fungi are million years old

COMMON MUSHROOM CAP GILLS VEIL STALK CUP MYCELLIAL THREADS

Kingdom Fungi (test review)
- Eukaryotic